Preparation of Anatase TiO₂ Thin Films with (OⁱPr)₂Ti(CH₃COCHCONEt₂)₂ Precursor by MOCVD

The reaction of titanium tetraisopropoxide with 2 equiv of N,N-diethyl acetoacetamide affords Ti(OⁱPr)₂(CH₃COCHCONEt₂)₂ (1) as colorless crystals in 80% yield. Compound 1 is characterized by spectroscopic (Mass and ¹H/¹³C NMR) and microanalytical data. Molecular structure of 1 has been determined by a single crystal X-ray diffraction study, which reveals that it is a monomeric, cis-diisopropoxide and contains a six coordinate Ti(IV) atom with a cis(CONEt₂), trans(COCH₃) configuration (1a) in a distorted octahedral environment. Variable-temperature ¹H NMR spectra of 1 indicate that it exists as an equilibrium mixture of cis, trans (1a) and cis, cis (1b) isomers in a 0.57 : 0.43 ratio at -20 .deg. C in toluene-d₈ solution. Thermal properties of 1 as a MOCVD precursor for titanium dioxide films have been evaluated by thermal gravimetric analysis and vapor pressure measurement. Thin films of pure anatase titanium dioxide (after annealing above 500 .deg. C under oxygen) have been grown on Si(100) with precursor 1 in the substrate temperature range of 350- 500 .deg. C using a bubbler-based MOCVD method